Re: [rhn-users] system load average and top

[Bret McMillan <bretm redhat com>]

On Wed, 12 Mar 2003, Mr.Anderson wrote:

> > 10:54am  up 42 days, 14:28,  2 users,  load average: 15.73, 14.17, 16.45
> > 284 processes: 279 sleeping, 5 running, 0 zombie, 0 stopped
> > CPU states:  5.9% user, 14.1% system,  0.0% nice, 79.9% idle
> > Mem:   514696K av,  473584K used,   41112K free,       0K shrd,   91628K
> > buff Swap: 1048088K av,   25280K used, 1022808K free       104152K
> > cached
> >
> > Does this makes sense? The CPU has no load and yet the load average is
> > high? Any ideas?
> 
> Umm...What do you mean "the CPU has no load"? It's at 20% used (79.9%
> idle). 20% usage is a lot depending on your CPU Mhz. If CPU is at 20%
> used, and the load average is at 15% at first glance seems ok. So a quick
> guess without looking at the processes is it's normal.

"load" as defined by top is not necessarily the same thing as cpu 
utilization.  I've been told that load is the average length of the 
ready-to-run queue for processes...  basically, you could theoretically 
have a bunch of stuff blocking on IO leading to a high load but low CPU 
utilization.

Of course, I may have a completely garbled understanding of the 
explanation, but, neverthless... :)

Bret